FusionFall Multiverse
by bLuewErewOlf25
Summary: RESPONSE TO CROSSOVERPAIRINGLOVER'S "X-OVER FUSIONFALL" CHALLENGE. When Dexter creates an invention that manipulates space and time, he damages the Multiverse. As a result, multiple universes are merged together, new ones following as time passes. 8 years and one long war later, five factions are formed and co-exist peacefully, albeit somewhat tentative. Too bad this is FusionFall.
1. Prolouge

**Hello! I was inspired by the challenge from Crossoverpairinglover, so I decided to write this fanfic. Let's see if I can focus long enough to finish it.**

 **I do not own any of these franchises.**

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 **FusionFall Multiverse**

 **Prolouge: Vision of a Coming Storm**

Have you ever heard of the Multiverse theory? Where there is a hypothetical set of infinite and finite universes, dimensions, parallels strung together in the great web of fate and karma, including ours? These universes present an infinite number of choices one could take; for better or worse, no one if I didn't eat this sandwich? What if I won this race? What if I sacrificed myself to save my friend from a gruesome death? Few believe such a tale, fewer try to pursue it. Those that do are either written off as crazy, or gain little helpers to achieve such an impossible goal: to access and move around the so called multiverse. Either way, they all fail miserably.

Of course, they don't live in a world where wizards go to school, animals talk, ninjas have demons trapped inside them, children possess robotic suits, and super powered people prowl the world for both good and evil.

My name is Luna Lovegood, 14, student at Hogwarts School of Witchcraft and Wizardry. I am also a seer. Yes, like what that fraud Trelawney claims to be, but unfortunately for her, she got the shorter end of the stick when it came to access to her powers. She could only glimpse things, and doesn't even remember what she saw afterwards. I, on the other hand, can see visions longer, more clearly, and can occasionally do it by sheer willpower, but that's a lot more tiring. They usually come at night, in my dreams. They've been more confusing and annoying in the recent days though. Glimpses of green, flames, stars snuffed out, cries, screams-

"Ouch!" A dish crashes to the ground, shattering into many little ceramic pieces. I hiss in pain; some of the shards hit my ankle and caused a nasty red gash to appear. I make sure to steady the other dozen plates I'm holding, and place them on the table.

"Sweetie, are you okay?" My father calls from downstairs, his voice full of worry. I smile. I love my father, I really do. Even after mother died, he made sure he was actively present in my life. He always made sure I was happy and content, even allowing me to make up those funny articles in the Quibbler. Poking at the Ministry with made-up charges is always fun, and is a good stress reliever in my opinion. My parents always said I was creative. My mother said being creative is good for a budding seer. It helps the seer be more cryptic and confusing to desperate idiots. Anyway, I'm rambling a bit.

"I'm fine Dad, thanks!" I shout, smiling. I wave my wand, muttering "Reparo", and place the now repaired plate on the table with the others. Then I tend to that annoying gash on my ankle, leaking a little blood. Oh, you might be wondering why I was carrying those plates when I have magic. Well, daddy always said that it won't hurt for you to do things the muggle way, so you can understand how they cope without magic. And so I was enlightened. I am SO getting a car when I turn eighteen!

I finish cleaning and healing my wound (the muggle way! Besides, I don't know healing magic), and look outside the window. It's a beautiful day outside. The birds are singing; flowers are blooming.

Somewhere in the world, a very punny skeleton sneezes all over a plate of spaghetti, much to the dismay of his brother.

On days like these, it's perfect for a game of catch, or picking flowers. In fact, I think I do just that. I run outside, laughing and breathing in the fresh air. I love my dad, and my home. Here…..I can just be free. I look up to the sky, and spot six humans in the air. Except, they had wings on their backs, and one of them seemed to be carrying a dog. I laugh and wave, and see one of them wave back. Now, I know what you readers might be thinking…..

'But Luna, there aren't any angels in the Harry Potter universe, are there?"

To answer your question, no, there are not. Though by now, I'm not so sure. Those winged-humans were the Flock, a group of teens who were experimented on by birth. What are they doing in my universe? Well, let me tell you a story, dear readers.

In another universe, a boy genius named Dexter was deciding on what invention he should create next, preferably something without a big red shiny button. So after countless hours of thinking, he came up with the _brilliant_ idea of messing with time and space. Now, normally this would be fine since he got all the schematics and kinks right. However, karma sucks, and his track record of working inventions is full of smoke and ashes, despite the inventions actually working to some degree. And it just so happened that countless other people around the Multiverse were performing similar experiments with space and time, including one Albus Dumbledore. To make a long story short, Dexter's invention worked. It also caused a chain reaction with other experiments across the Multiverse, and started ripping holes in the time-space continuum. As a result, many universes, or at least parts of them, were pulled together and merged.

I know. Crazy right?

And so, when each inhabitant discovered what happened, they turned to their respective heroes and protectors for guidance. And said heroes and protectors, when meeting their other-dimensional counterparts, decided to immediately work together to restore the balance and spread sunshine and rainbows…..NOT! Hehehehehe, you think a bunch of paranoid heroes and neutrals, dealing with their own problems from different ends of the Multiverse, could work together just like that?! No, most of them distrusted each other almost immediately, with their varying morals and ideas. The few open-minded ones were lucky to befriend those from dimensions not of their own, but like I said, few. And let's not even go into the problem the villains posed when they started banding together.

With the amount of tension in the sir, it was no surprise that war broke out.

 _The air was filled with smoke and screams. The ground was charred and torn asunder. Several bodies lay on the ground, some bloody, most broken. It was hard to tell if they were dead or unconscious. Two figures fought in the air above the ruined battleground, one in red and blue, the other in orange with spiky glowing yellow hair. They traded blows with such ferocity; onlookers would only see two colored blurs. On the ground, a pale muscled man, with tattoos red as blood, clashed swords with an orange haired man dressed in a black robe. Nearby, a skirt wearing figure seemed to dance out of the way, as glowing white spears embedded where she once stood. She pulled her own spear out of a gem attached to her head, and charged. The thrower, an eye patch wearing fish dressed in armor, growled and stood determined, ready to take her on. An old man, wrapped in gray, held his staff high and began chanting. His opponent, an old man dressed in blue and with a beard that would put Dumbledore to shame, flew up high to avoid the spell and began casting ice bolts at the grey wizard. One thing all combatants held in common: They would protect their homes at any cost._

The war lasted for 5 years, but it felt like ages to those who participated. And to top it all off, the rips never closed or lessened in number. As the war progressed, more and more parts of the Multiverse appeared, some coming by individuals, others coming by cities or even countries. One way or another, they all chose sides.

Then the war stopped, as quickly as it started. The five factions: The Federation of Virtua-Gama , Animania , Toonopolis, Lituratopia, and the Republic of Comivale signed a peace treaty and established their terms and boundaries. The person who headed this, the one who stopped the war, was a human child. Shocking isn't it? A mere child, not even a first year, did what experienced diplomats and peace activists couldn't. However, according to those who witnessed what happened, the sheer determination and mercy that was rolling of this child….it was indescribable. Heh, he sounds like a good kid.

Anyway, that was three years ago. We've managed to move on by now (surprisingly quick right?), though the war is still lingers on everyone's minds. But hey, the faction-states had begun opening up to each other a year ago. I mean, while they aren't exactly allowing tourists, they've opened up to trading so I guess that counts for something right? The only problem is that no one has managed to figure out how to stop the sudden portals appearing and depositing a new dimension. It's become something of a silent competition to take in as many inhabitants of each new dimension into one's faction as possible, depending on where the next portal appears. Heck, even the muggle news keeps tabs on it. So yeah, that's basically what's been happening around this mashed-up world.

I lay on the grass, taking in the bright blue sky and the fluffy white clouds. In just a month, I'll have to go back to Hogwarts. Back to walls, confining spaces, drama, prejudice, bullies…

'Enough depressing thoughts Luna. You have Ginny and Neville to talk to; it's not like you don't have friends. Of course, all Ginny talks about is Harry Potter these days, and Neville is…" I lose myself in my thoughts.

Dusk soon approached. I yawned and made my way back to my house. It's almost time for pie!

"Dad, I'm ho-"I'm cut of mid-sentence by a blinding, searing pain in my head. I yell in pain, losing my balance and falling to the ground. My father runs to me in worry, shouting something, but I can hardly pay attention.

 _A giant green monstrosity smiled cruelly as his forces clashed with the defenders. His form seemed to radiate evil. "Soon…"_

 _A more battle-worn me ducked green bolts of death from….a green slime version of me? Only, my evil twin had red eyes and carried a wand, while I held a staff. I fired a bolt of lightning as my twin sent more Avada Kedavras._

 _A boy I recognized as Dexter typed furiously, several screens showing a loading bar. I saw myself and a few others I didn't recognize watching._

 _A small child-like goat monster joined hands with a human child wearing a purple and blue striped shirt. Both bodies' glowed, their white forms merging. When the glow died down, an adult version of the goat monster stood at ready, multi-colored fire forming in his hands._

 _Many heroes and villains gathered on top of a cliff, looking down to see what could be called an army of teens, fully equipped with an. Everyone stares overhead at the giant green planet in the sky._

 _Bloody, bruised, determined. The defenders of this planet glared at the green overlord. They would never give up._

 _Many more visions flash through my mind. It's too much….._

I shuddered as the visions ended. My head was still wringing with pain. I felt completely exhausted. My father quickly helped me up and had me sit on a chair. He handed me some butterbeer as he checked for any lingering injuries.

"My daughter, are you okay?" He asked, concern evident in his eyes.

"I'm fine dad. My seer abilities just decided to act up" I muttered, gripping the mug of butterbeer as my mind whirled with this new information. Who were those people I was with? Who was that giant green slime monster? Why was there an evil slime twin of me? What did this mean for the planet? The more I thought about it, the more conclusions came up. None of them were pretty. I realize that I saw that green alien (There is no other explanation) before. In my previous visions...he was standing over a dying world. I gulp and shudder once more. This…this is…oh no…

"Luna? Are you okay? What…what did you see?" Xenophilius Lovegood, my loving father, who has always cared for me when my mother passed away…..I saw what I was part of in those visions. If I tell him, he might try to follow…..he might get hurt….he…he might….

"…Nothing father. Nothing you should be concerned about. Just a bunch of nargles trying to take over the earth. I also have a headache" I finally say, closing my eyes and taking a sip from my drink. Thankfully, my father doesn't pry and heads off to get some headache-removing potions. I let out the breath I didn't know I was holding. My visions have never been wrong before. Judging by the frequency and intensity of these visions; whatever is going to happen will happen soon.

I can only hope the world is ready for the coming storm.

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 **See if you can guess any of the characters hinted~**


	2. A Whole New World

**Hey, it looks like I CAN focus enough to make another chapter!**

 **If Luna seemed a bit more snarky/sarcastic? last chapter, well, think of Naruto Uzumaki. People have been bullying him for how a long, long time. So he created a mask that would let him interact with people without, you know, snapping. The same can be said for Luna.**

 **And speaking of the lovable blonde...Luna? If you will?**

 **Luna: bLuewErewOlf25 does NOT own any of the following characters appearing in this chapter. If he did, the world would be full of nargles and chaos.**

 **HEY!**

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 **Chapter 1: A Whole New World**

" _And now we return to Dimension Watch, where a new batch of portals has opened up last week. We have reports coming in that Katniss Everdeen, nicknamed "The Girl On Fire", and Peeta Mellark have joined Literatopia. Taken from a post-apocalyptic world, where children are forced to kill each other, Katniss rebelled against the government by breaking the rules of the games and bringing her companion out alive. Let's hope she doesn't lose her spark soon….or her potential boyfriend."_

An image of said two flashes on the television screen, next to an African-American woman who was reporting.

" _Aside from those two, a new place named DunBroch has appeared on the map of Toonopolis, effectively becoming part of the faction. This alternate Scotland is home to the brave princess Merida and her family. After the queen was turned into a bear, the princess went on a journey with her to find a cure for her mother's condition. After a long journey there and back again, they freed a corrupted prince from his curse and managed to find the cure: Love."_

The image is replaced by one containing an orange-haired girl carrying a bow, next to a more regal looking woman.

" _And let's not forget our own faction ladies and gentlemen! The Shoshone National Forest has appeared within our borders, and is now open for visitation. You can take long walks, go camping, hiking, and enjoy the wildlife. That is, if it wasn't burned down. That's right, not two days after it had appeared, a forest fire started and burnt most of the forest to the ground. What are left are a few rabid animals, burnt timber, and several campsites. Luckily the fire was put out before it could spread to the surrounding areas. "_

The final image shows a burning forest, a watch tower seen in the distance.

 _No new additions for Animania or the Republic of Comivale yet, but there's always this week. Finally, I'd like to say this job is much easier than shooting zombies and running for your life. This Rochelle reporting for Dimension Watch; now back to you Mettaton!"_

The image on the screen switched to a feminine looking robot colored black, grey and pink. He seemed to be smirking at the camera.

" _Thank you darling~.Now for our next report…."_

"Come on Frisk, don't you have anything better to do?" A voice spoke from behind him, causing the pacifist child to jump up in surprise. He turned to find a smirking Asriel Dreemurr.

"Asriel! You scared me!"

"Sorry Frisk. But really, why do you love watching the news so much?"

Frisk shrugs his shoulders and smiles at his adopted brother. Asriel had changed a lot over the past 4 years. From the shy and socially-awkward goat boy he was after being given a second chance in life, he was now a confident, friendly and mischievous pre-teen.

"I find things that happened around the world interesting. Besides, I want to make sure nothing bad happens between the factions."

Asriel nodded. It sounded like a reason Frisk would say. Then he looked at the flat-screen TV displaying the news.

"Hey, since when has Mettaton been a news reporter?"

"Well, remember when I headed that treaty to bring peace to all five warring factions some years ago?"

Asriel nodded; he remembered the war clearly. How could he not? Mount Ebott was taken by a random portal and dumped into this mashed up dimension during the final year of the war. Needless to say, the sudden change of scenery was a shock to all the monsters, and the humans who happened to be living in the same town as the monsters. Sans was in a pretty bad mood with what happened.

He remembered the two individuals who came to welcome the monsters to this dimension: An anthropomorph named Fox McCloud, and a blue hedgehog named Sonic. Asriel smirked as he remembered the following spar between Sonic and Undyne. Sonic's expression was priceless when he realized Undyne could keep him from using his speed as an advantage. She REALLY doesn't like her opponents running away from the handicap however, Sonic proved to be craftier than what they expected, learning how to use his Soul quickly and using numerous power-ups to compensate for his lack of speed. The fight ended in a draw, and Undyne and Sonic became fast friends.

Sonic even tried flirting with Undyne once. Alphys didn't take that very well. Who knew the nerdy lizard could match Sonic's speed when motivated and have for mercy?

When Fox told them about the current condition of the multiverse, they were all shocked, none more so than Frisk and Sans. The Multiverse slowly being merged together is hard for anyone to take in and to top it all off, a war had been going for the past four years. Frisk was horrified when he learned that the residents of Ebott will be forced to choose a side, lest the five factions destroy the town as they fight for it. He recognized the need for violence when necessary, but he detested killing others. Forcing the monsters (and few unlucky humans) to fight a war or else….it made Frisk feel sick.

After a quick meeting between the boss monsters, Asgore decided to join the Federation of Virtua-Gama, much to Fox's and Sonic's relief. They were worried they would have to fight there new Town quickly became a major, if not central hub for the faction. Various individuals come and go from Ebott Town, whether just visiting or for war related purposes.

Undyne and Asgore were regularly seen on the battlefield, being the two most active members from the Underground. Papyrus tried to go with them, but Asgore made sure to assign him to guarding and the town, to keep him out of the way of danger. That, and Sans would hold Asgore responsible for Papyrus' death and try to kill him, king or not.

Muffet and Alphys had each set up shop in Ebott Town, Muffet with her bakery and Alphys with her lab. With the discovery of the healing properties of monster food, the heads quickly used this to their advantage. Soldiers made sure to have at least one Spider Doughnut on their person at all time; it made Muffet very happy and VERY rich. Even when the war ended, Muffet was content with the money she made making her pastries.

Alphys, on the other hand, had set up her lab once more. She lives there with Undyne, which is why half of the house is shaped like a fish. She's part of the Science division of Virtua-Gama, and is one of the top scientists in the faction along with a few others. She was entirely fascinated with each universe and their inhabitants, and wanted to learn all she could about them. She was especially happy when she learned that every anime she had ever watched existed in the Multiverse, with the exception of Mew Mew Kissy Cutie (both versions). Alphys had really wanted to head over to the Animania faction and talk to her anime idols, war be damned. Unfortunately, walking into another faction's territory during a war, without a mission or the intent to betray his/her own faction is considered suicide.

She was very happy when the war ended.

During the final moments of the war, Frisk had rushed to the battlefield where the five armies were clashing on the back of a butter colored pegasus. He, Asriel, had been fighting this kid that transforms into a red dragon when he saw the two flying overhead. He had immediately broke off to help Frisk in whatever he needed, only to find a barrier made of hearts covering the middle of the battlefield, with Frisk and the some of the primary leaders of each faction inside. According to Frisk, what transpired in that barrier was-

"Hey Asriel, you alright?" Frisk asked the goat boy, who had been staring of into space.

Asriel shook himself out of his thoughts and smiled. "Yeah, I'm good. And I do remember the treaty Frisk." The treaty was what kept the peace between the factions for the past three years. Things like boundaries and terms, trades and such were kept on the original document. Frisk held the original copy while each primary leader had self-updating copies. However, only those written on the original copy had any value. So if one was to change details on his or her copy and used it to validate something, the others would check with the other copies to see if this proved to be true, or ask Frisk to check the original.

Of course since this would prove to be false, the resulting consequences would be horrible, and humiliating. Tony Stark still sulks every time someone mentions the Chicken Dance, something a certain captain was all too happy to exploit.

Normally people would wonder if Frisk would ever abuse this and change the document. Those who've met him however, would say that there's no bone in his body that would cause him to do that, even if some people try to convince themselves otherwise.

"What about it?"

"You remember how I allowed the creation of Dimension Watch?"

Asriel nodded. Most major changes involving multiple factions had to go through Frisk before being made official, seeing as he has the original copy. Dimension Watch is an organization that involves all the factions, so it counted.

"Well, Mettaton wanted to try something new for a change, and thought back to one of the quiz shows he gave me. So he asked me if he could become a news reporter, seeing as I'm one of the biggest higher ups there are. It would also get him more viewers and a chance for shameless advertising. So I pulled some strings and allowed him."

Mettaton had disregarded the entire war at first and pursued his dream of becoming a star, taking Napstablook, Shyren and Burgerpants with him, with a reluctant Doggo tagging along. Together, this strange band journeyed from place to place, even those in other factions. In every place they hit, they performed shows and concerts, flying cameras viewing their every movement. Of course the other factions didn't take kindly to these intrusions, but this is Mettaton we're talking about. He's not one to let minor details stop him. Even after the war ended, he and his band kept of performing around the world. The audience simply loved them.

Asriel grinned. Frisk thought he looks even more adorable when he smiles. "Wow! How long do you think he'll keep that gig before getting bored?"

"I'd give it some weeks, since he's going to milk the job for all it's worth. After all, he loves having a ton of fans."

Frisk was smirking at this point. Asriel looked at him with apprehension, and some resignation.

"Frisk…no…"

"A Metta-TON of fans"

Asriel groaned and facepalmed. Frisk laughed at Asriel's expression.

"Oh my god! I blame Mom and Sans for corrupting you. You three and your damned puns."

Frisk just laughed harder.

 ***LINEBREAK***

Frisk sighed in happiness as he looked over Ebott Town from his balcony. He and Asriel lived with their mother Toriel, Sans, Papyrus and Asgore. Yeah, Toriel and Asgore had gotten back together in the past four years they've joined this new universe. It had been a slow process, and had pushed Frisk's romantic skills to the limits. But in the end, Toriel forgave Asgore and the two happily reconciled.

Their house was located at the end of the village, and overlooked the entire area. It was as big as a mansion due to the number of inhabitants, and the numerous guest rooms created for special occasions. Underneath was Sans' lab, which only he and Frisk knew about. This is where Sans runs his tests to see if he could fix the rips or even use them to their advantage. So far, the tests have been unsuccessful. Asgore and Toriel shared a room, Frisk and Asriel shared another room, and Sans and Papyrus had their own rooms.

Looking down, he spotted many of his friends, new and old, interacting with each other. He saw Monster Kid playing with two other boys in striped shirts, Ness and Lucas. A monkey with a red cap and shirt, and a blonde male dressed in teal with a monkey-like tail were cheerfully evading the Mad Dummy, who looked rather pink at the moment. Speaking of pink, Kirby was going around and stealing everyone's food. The sight made him chuckle a bit.

Everyone was happy. There was no war, and he could keep tabs on multiple situations thanks to Dimension Watch. He had his family, his friends, and had stopped a five year war. So what was this cold feeling inside of him? It is the feeling of something horrible approaching? Or is it….possibly….

Boredom?

'Come to think of it, that was the reason I kept resetting so many times before Sans set me straight.' Frisk mused to himself. He always did have a thirst for adventure, which caused him to keep resetting the Underground over and over. Chara certainly didn't help when she caused Frisk to go Genocidal. 'Chara' Frisk shuddered. That name brought both sadness and painful memories of his past sins. Chara had died during the war, protecting Frisk. On her dying breath, she made Frisk swear to NEVER reveal the cause of her demise. She knew Frisk wouldn't want the monsters to cause another war, if only to take revenge on her murderer.

Frisk shook his head and cleared any thoughts about his dead friend. Sans had confronted Frisk about the resets and threatened him with their friendship if he ever reset again. When was taken away, Sans had asked him if he was responsible for it. Frisk had responded, as honestly as he could, "No".

'All those resets….I swore I would never touch that again. And I intend to fulfill that promise, just like I would keep my promise to Chara.' Frisk slowly smiled. 'But this is a new world, with numerous possibilities. I can already hear adventure calling me'.

Frisk exited the balcony and ran downstairs. He grabbed a piece of paper and pen, writing a note for Toriel when she got back from her work as a teacher. She would be extremely worried if he didn't tell her that he left, not to mention rude on his part. He sprinted out of his house, giving casual greetings to his friends, and spotted his target in a clearing.

A yellow-orange anthropomorphic fox was treated to the rare instance of fifty-seven inches of cuteness slamming into him. "TAILS! So good to see you!" Frisk yelled as he hugged the twin-tailed fox.

Tails gave an awkward grin, given the force of the pacifist child's hug. "Good…to…see you too….Need…air"

Frisk released the hug, still smiling. He asked. "What are you doing here?"

"Oh, I just had to make a quick stop to refuel my plane. And maybe grab a Spider Doughnut or two."

"Do you mind if I tag along with you?" Tails looked at him in some surprise.

"Why? Won't your parents get worried about you?" Frisk shrugged the concern off and replied. "I already wrote a note to mom to counter that. I've been getting a bit bored to be honest. I wanted to explore the world more, and not just within our state. Since Mettaton hasn't dropped by yet, you were the next best thing given your groups connections with some people from Toonopolis. So can I?

Tails had one more question to ask. "Why not use Dimension Watch for that purpose?"

Frisk responded cheekily. "You were nearer. And mom could easily find me that way." Satisfied, and a bit amused with his response, Tails nodded his head in agreement.

"Okay Frisk, you can come along."

"YAY! Let's go before-"

"Frisk!"

Frisk turned around to spot Asriel running up to them. He panicked.

"Asriel! Listen, I can explain-"

"Don't bother, I heard everything."

Silence reigned through the clearing. Neither brother spoke, while Tails eyed both of them nervously. Asriel stared blankly at his brother, before grinning.

"Which is why I'm going to come with you!"

"WHAT?!"

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 **If you have any comments on my writing style, or things that could be improved, then say it! Just no flaming. I'm not using up my water for that.**

 **Tails is older in the fic, about 13 or 14.**

 **Asriel and Frisk are 12** **.**

 **Update: 3/29/2016**

 **I fixed some spelling errors and added a line or two. Also, Crossoverpairinglover suggested I make a list of every character used in the chapter. Well okay then. But you can go guess the cameos yourself. I'll leave hints.**

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 **List In Order Of Appearance:**

 **Rochelle (Left For Dead 2)**

 **Frisk Dreemurr (Undertale)**

 **Asriel Dreemurr (Undertale)**

 **Miles "Tails" Prower. (Sonic the Hedgehog)**

 **Universes Present:**

 **Undertale**

 **Sonic the Hedgehog**

 **Hunger Games**

 **Brave**

 **Firewatch**

 **Star Fox**

 **Earthbound**

 **Donkey Kong**

 **Final Fantasy**

 **Kirby**


End file.
